Conventionally, an electrical connection box is known in which a circuit portion having electronic components mounted thereon is housed inside a case. JP 2014-82844A discloses an electrical connection box that includes a circuit portion having an electronic component mounted thereon, an electrically conductive heat dissipation member that dissipates heat from the circuit portion, and an electrically conductive case that, along with the heat dissipation member, houses the circuit portion. The case that covers the circuit portion is connected to a vehicle ground via a relay ground terminal, and electromagnetic noise generated by high-speed switching of the electronic component or the like is shielded by the case.
In the case where an electrical connection box and a power storage element are installed separately from each other in a vehicle or the like, electrical wires and connectors are needed in order to connect them, and therefore there are problems such as an increase in the number of components and an increase in weight, as well as power transmission loss caused by resistance in the electrical wires. In view of this, consolidating the circuit portion of the electrical connection box and the power storage element is preferable due to making it possible to suppress an increase in weight caused by electrical wires, connectors, and the like, as well as power transmission loss caused by resistance in the electrical wires.
JP 2005-94943A discloses a capacitor unit that includes a capacitor block, a control circuit portion constituted by a charging/discharging circuit for performing charging or discharging of the capacitor block, and a case that houses the capacitor block and the control circuit portion. This control circuit portion is incorporated in the case in the state of being covered by a shielding case that is divided into upper and lower portions.
However, similarly to the electrical connection box used in the case where the control circuit portion and the power storage element are arranged separately from each other, in JP 2005-94943A, the entirety of the control circuit portion needs to be covered by the shielding case (case), thus leading to the problem that simplification of the configuration is not easy.
The present invention was achieved in light of the above-described circumstances, and an object thereof is to provide an electricity storage unit that makes it possible to suppress the influence of noise from the circuit portion and to consolidate the circuit portion and the power storage element.